Flexible treated material and method of making the same



B. H. F. RICHARDS ET AL 97,651

FLEXIBLE TREATED MATERIAL AND METHOD OF MAKING THE S AME Feb. 14, 1933.

Filed March 17, 1950 Patented Feb. 14, 1933 UNITED STATES PATENT OFFICE BARON HUBERT FREDERICK RICHARDS AND ARTHUR H. HAROLDSON, OF VALPARAISO, INDIANA, ASSIGNORS, BY MESNE ASSIGNMENTS, TO CONTINENTAL DIAMOND FIBRE COMPANY, OF NEWARK, DELAWARE, A CORPORATION OF DELAWARE FLEXIBLE TREATED MATERIAL AND METHOD OF MAKING THE SAME Application filed March 17,

This invention relates to the method of treating fibrous materials, and particularly to the method of treating fibrous materials with a resinous varnish, such as phenol and formaldehyde condensation product.

The primary object of the invention is to provide a new and novel method to produce an insoluble non-fusible but substantially flexible article with the use of a resinous varnish, such as phenol formaldehyde.

Another object is to provide a new article of manufacture which can be used for various purposes wherever a flexible non-conductor or insulator is required, such as insulating tape for electrical connections.

Another object is the method of treating creped paper or other similar fibrous material, in which the fibers are broken up, which consists in impregnating the fibrous material in a resinous varnish bath, pre-curing the. material which consists in heating it in an oven until the solvents are driven off, and then finally curing the product by subjecting it to a heat and pressure operation.

The invention comprises in general the method of creping, crimping, or breaking up the fibers in a sheet of fibrous material, such as paper, passing the fibrous material with the fibers broken up through a varnish bath, pre-curing the material to drive off the solvents and subjecting the material to heat and pressure.

The accompanying drawing illustrates a selected embodiment for carrying out the method, and the views therein are as follows:

Fig. 1 is a detail perspective view of a sheet of paper or other fibrous material which has been creped or crimped to break up the fibers.

Fig. 2 is a detail sectional view of a piece of crepe paper which has been run through the varnish bath, and then subjected to the final heat and pressure operation to provide a finished panel.

Fig. 3 is a detail perspective view of a piece of material, such as shown in Fig. 2, showing the flexible characteristics of the final product.

A sheet of ordinary paper may be made or put through certain apparatuses to pro- 1330. ,Serial No. 436,268.

greater surface to absorb the liquid resinous varnish. The breakingup of the fibers also rovides a material which is relatively-fiexi- 1e. After the material passes through the resinous varnish bath the excess varnish is wiped therefrom, and the material is put in an oven where it is subjected to heat for a period long enough to drive oif the solvent. 7

This sheet of fibrous material is then subjected to a heat and pressure operation for a predetermined period, whereby the resinous varnish is converted into an insoluble non-fusible product.

If a sheet of ordinary paper without the fibers broken up were passed through theresinous bath, and then subjected to the heat and pressure, the result would be a sheet of very hard tough brittle insoluble non-fusible material. The use of a creped paper, however, or any other fibrous material, which has the fibers broken up, produces an insulating sheet 9 having a relatively smooth surface 10, Fig. 2, and which is relatively This sheet may then be cut up into strips 11, such as shown in Fig. 30, and used as insulating tape for electrical connections.

The phenomena produced are evidently due to the breaking up of the fibers of which the material is made, While it is well known that a sheet of paper passed through a resinous bath and then cured with heat and pressure, produces one result, actual practice has taught that by first breaking up the fibers and then subjecting the sheet having the broken up fibers through the very same kind of a bath, an entirely difierent article is produced.

The invention provides a flexible non-con- 1 ductive insulating material, for which there is considerable demand, and which may be readily and economically manufactured. The breaking up of the fibers causes the material to be flexible instead of stiff and brittle as When the fibers are not broken.

It is to be understood, of course, that the invention is susceptible to various embodiments and adaptations as will be apparent in the appended claims.

Having thus described our invention, What We claim as new and desire to secure by Letters Patent is:

l. The method of providing a flexible, insoluble, non-fusible product, which consists in passing a piece of crped or crimped fibrous material through a bath of phenol and formaldehyde condensation product to impregnate the material, and then subjecting the impregnated material to a heat and pressure operation.

- 2. The method of making a flexible, insolu- I ble, non-fusible layer, which consists in impregnating a sheet of crped or crimped fibrous material With a suitable heat convertible complex and then subjecting the impregnated sheet to heat and pressure for the purpose of curing or converting the complex to its final inert condition.

3. A flexible, insoluble, non-fusible mate rial comprising a sheet of crped or crimped fibrous material, and a suitable heat converted complex of insoluble, infusible properties substantially uniformly distributed through the fibrous material.

4. A flexible, insoluble, non-fusible, material comprising a sheet of crped or crimped fibrous material, and a phenol formaldehyde condensation product in its final infusible, insoluble state substantially uniformly distributed through the fibrous material.

In Witness whereof, we have hereunto subscribed our names.

BARONHUBERT FREDERICK RICHARDS. ARTHUR H. HAROLDSON. 

